The present invention relates to a plug device for a standard electrical or optical connection cord provided at at least one of its ends with a plug presenting a body provided with an external mechanical latch.
At present, in the field of electrical installations, the main standards for ruggedized industrial networks have been created by the suppliers of control units: PROFIBUS(trademark) from Siemens, FIP(trademark) from Txc3xa9lxc3xa9mxc3xa9canique, etc.
The present trend is to escape from the constraints associated with such suppliers of control units by using a data transfer network on-site that is open, i.e. a network that is not dependent on any particular supplier of control units and that constitutes a genuine worldwide standard.
Ethernet, which is a network already in use in offices for interconnecting computers and their peripherals, satisfies these conditions. The connectors used are known as the xe2x80x9cRJ45xe2x80x9d type. Connections are constituted by an optionally-shielded standard cord having plugs that are likewise standard mounted at its ends, each plug presenting a body which is provided with an external mechanical latch that can be retracted by pressing on one end of the latch. Naturally, the latch is used for mechanical fixing when making a connection with a jack.
Accompanying FIG. 1 shows the end of a standard cord fitted with a plug of a type that is also standard in the RJ45 or RJ11 system.
There can be seen the cord 10 and its plug 12 which comprises a body 14 that is generally overmolded onto the cord 10. A mechanical latch 16 is provided on the outside face of the body 14, which latch can be moved into an inactive position by a tongue 18 acting as a control lever.
Although that type of connector is well suited to the conditions that apply to the Ethernet standard, it is not at all suited to the industrial production environment in which splashes of liquids, shocks, untimely tugs on the cord, vibration, electromagnetic disturbances, etc., can all be encountered. Connection cords of the RJ45 or RJ11 type present the additional advantage that they are now standard cords which are available ready-calibrated with two over-molded RJ45 or RJ11 plugs, one at each end.
One solution for adapting RJ45 connectors to the constraints of the industrial environment would be to separate the standard cord from its plugs and replace those plugs with plugs of a conventional type used in an industrial environment.
Nevertheless, it will be understood that that would present two drawbacks:
firstly, because of the over-molding, eliminating the original plugs, and then wiring new plugs to the cord would lead to additional costs; and
secondly, the benefit of the cord fitted with its two over-molded plugs being already calibrated is lost, and this runs the risk of reducing overall performance.
There therefore exists a real need to be able to transform a standard electrical cord fitted with a RJ45 type plug or the like into a standard cord fitted with a plug that is compatible with the industrial environment, while avoiding the drawbacks of the solution outlined above.
In the field of transmitting information using light signals, there exist problems that are similar or identical. Standard optical fiber cords are available having at least one plug body at at least one end, which body is provided with a mechanical latch. As with electrical cords, optical cords of this type are not adapted to use in an industrial manufacturing environment.
There thus exists the same need to transform a standard optical connection cord into a cord fitted with a plug that is compatible with an industrial environment.
To achieve this object, the present invention provides a plug device for a standard electrical or optical connection cord provided at an end with a cord plug fastened to the cord and having a body which includes an external mechanical latch fitted with a control lever having an active position and an inactive position, the plug device being characterized in that it comprises:
a plug body;
a plug adapter distinct from the plug body and having external fastening means for engaging in said plug body;
a packing body including packing of cylindrical shape and a screw thread; and
a link part having a first end for connection with said plug body and a second end provided with a screw thread for co-operating with said screw thread of said packing body;
said plug adapter having an internal profile suitable for receiving said cord plug body and having fastening means for engaging the cord plug body and for holding said latch of the cord plug body in its inactive position;
said packing body, the packing when a rest, and said link part all defining respective internal passages of sufficient size to pass the cord plug body; and
screwing the packing body onto said link part causing said packing to be compressed, thereby clamping said packing onto the standard cord.
It will be understood that by means of the invention is possible to insert the cord plug into the elements constituting the plug device so as to house the plug body inside the protective plug adapter. Furthermore, the plug adapter is shaped in such a manner as to hold the mechanical latch of the cord plug in its inactive position. In this way, the connection between the plug and the corresponding jack is made in conventional manner merely by the plug body.
It should also be emphasized that by compressing the packing, not only is the plug device assembly sealed, but the standard cord is fastened mechanically to the plug device in addition to the main fastening that results from the cord plug cooperating with the plug adapter.
Finally, and above all, the invention makes it possible to adapt the cord to an industrial environment without any need to separate the plug from the cord. The advantages relate equally well to the optical cords and to the electrical cords.
In a preferred embodiment, said plug adapter is constituted by two distinct parts, each defining a portion of the internal profile suitable for receiving said cord plug body, thereby enabling said two parts of said adapter to be put into place in succession on the cord plug body.
It will be understood that in this preferred embodiment, it is easier to mount the cord plug in the insulating adapter, since each of the parts can be put into place in succession in a lateral direction relative to the body of the cord plug.
Also preferably, each part of the plug adapter has a portion in relief forming an abutment suitable for co-operating with a portion of the latch of the cord plug when said latch is in its inactive position. This characteristic is particularly advantageous since in this way axial fastening between the cord plug and the plug adapter is obtained by a portion of the plug which has standardized dimensions. The plug adapter can thus be used regardless of the type or the manufacturer of the cord.
Other characteristics and advantages of the invention appear better on reading the following description of various embodiments of the invention given as non-limiting examples.